You're probably already wondering if you're carrying a boy or a girl, but the physical signs of gender aren't apparent yet.
Although the sex of your baby was determined at the moment of fertilization, it will not yet be apparent whether the embryo is male or female.
At this stage of development, the external genitalia have exactly the same appearance (almost nonexistent). In a girl, no uterus or tubes have formed internally. The ovary in a female embryo and testes in a male embryo are currently just ridges of tissue, without any of the characteristics of either reproductive organ.
Incredibly, your baby's heart has already developed, with four chambers beating at about 160 beats per minute. The common tube leaving the heart has divided into the two main blood vessels: the aorta takes your baby's oxygen-carrying blood to his body and the pulmonary trunk takes his blood to the lungs. Valves within the heart ensure that the blood only travels one way and all of the major blood vessels are now established.
Your baby's eyes appear open because the eyelids have just started to appear and have yet to fuse. In reality, they won't properly open until week 26. Pigment is just starting to accumulate within the retina of the eye. The developing lens is supplied by a single blood vessel in the optic nerve, which will later disappear.
Ask A... Doctor
You may be prescribed antibiotics by your doctor since there are some that can be taken during pregnancy. Penicillin-based antibiotics are usually prescribed, or if you are allergic to these your doctor will be able to offer other safe alternatives.
Never take antibiotics that have not been prescribed for you specifically. The following antibiotics should not be taken during pregnancy:
- Tetracylines taken during pregnancy can adversely affect the development of an unborn baby's bones, and may cause some discoloration of the enamel on the baby's teeth.
- Streptomycin can cause damage to the ears of the developing baby and result in hearing loss.
- Sulphonamides can cause jaundice in the baby.
Excerpted from Pregnancy Day by Day.
Copyright © 2008 Dorling Kindersley Limited.
Buy this book now!